Do Road Salts Cause Environmental Impacts?

By Scott Stranko,

Rebecca Bourquin, Jenny Zimmerman, Michael Kashiwagi, Margaret McGinty,

and Ron Klauda

Monitoring and Non-Tidal Assessment Division

Resource Assessment Service Maryland Department of Natural Resources

580 Taylor Avenue, C-2 Annapolis, Maryland 21401

April 2013

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Introduction Hundreds of reports and scientific papers have examined potential environmental problems associated with the use of salt to de-ice roads. Appendix A provides a list of some of the most pertinent recent literature. This document is a brief review and summary of some of that literature. Our document also describes results from the Maryland Biological Stream Survey (MBSS) data that are relevant to this topic. The MBSS is led by Maryland Department of Natural Resources (DNR) staff with support from the University of Maryland Appalachian Laboratory staff. Along with this summary, we recommend three other documents because they offer useful information. For a thorough technical review of ecological literature on the effects of salt, Miguel Cañedo-Argüelles et al. (2013 in Environmental Pollution volume 173) “Salinisation of Rivers: an Urgent Ecological Issue” is recommended. For a non-technical report, we recommend the one written by staff at The Cary Institute of Ecosystem Studies (December 2010) titled “Road Salt: Moving Toward the Solution”. Along with general information about road salt impacts, the Cary Institute report offers solutions, costs, and alternatives. The Canadian Council of Ministers of the Environment (2011) provides a report titled “Canadian Environmental Quality Guidelines for the Protection of Aquatic Life: Chloride”. This report describes chloride toxicity in a regulatory context and presents justification for the water quality guidelines used in Canada. According to The Cary Institute of Ecosystem Studies (www.caryinstitute.org), salt was first used in the United States to de-ice roads in New Hampshire in 1938. By the winter of 1941-1942, a total of 5,000 tons of salt were spread on highways in the U.S. annually. Between 10 and 20 million tons of salt are used today. This increase in the use of road salt has caused an increase in the salinity of the Nation’s ground and surface waters that threatens our drinking water and environment. Concentrations in surface and groundwater will continue to increase, perhaps for decades, even if road salt use is completely stopped because there is a lag between salt application to roads and salt showing up in groundwater (Jackson and Jobbagy 2005; Godwin et al. 2003) . In most areas, concentrations of salt in surface waters near roads exceed ambient stream and groundwater concentrations. The rate of export (flushing) of salt from ground and surface waters is usually slower than the rate of input. Ambient salt concentrations will likely continue to increase until input concentrations approximately equal ambient concentrations (Kelly et al. 2008; Harte and Throwbridge 2010; Perera et al. 2013) or road salt application is reduced substantially. Although other alternatives exist, the most commonly used “salt” for road de-icing is sodium chloride. Some studies summarized here directly examined the environmental effect of this salt from road run-off. Many studies focused only on the chloride ion and other studies used the specific conductance of water as a surrogate for salt in areas where de-icing occurred. Since specific conductance is a measure of dissolved salts in solution, it tends to be higher in water with salt compared to water without it. However, specific conductance can be high due to the presence of other naturally occurring and anthropogenically dispersed ions such as calcium and bicarbonate ion. Therefore, there is no way to directly adjust specific conductance values to determine sodium chloride concentrations. Although the chloride ion occurs in compounds other than those used to

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de-ice roads and other salts are sometimes used for de-icing, sodium chloride used for road de-icing is the most common anthropogenically dispersed salt found in ground and surface freshwater. Thus, chloride concentration typically provides an accurate representation of water’s sodium chloride content. Figure 1 shows the relationship between specific conductance and chloride concentrations from 2,482 samples taken from Maryland streams as part of the MBSS.

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Figure 1. Chloride concentrations and specific conductance measured at 2,482 Maryland Biological Stream Survey sites.

The natural salinity of aquatic environments varies widely. Sea water typically contains about 35,000 mg/L salt and about 19,000 mg/L chloride. In estuarine waters, the ratio of chloride concentration to the total salinity is consistent regardless of total salt concentrations. Therefore, total chloride concentrations can be easily calculated in estuaries if the total salinity is known. Water that is considered “freshwater” typically contains less than 500 mg/L salt and less than 300 mg/L chloride, but the ratio can vary widely (Kaushal 2009). The average salinity of inland (“fresh”) waters environments is about 120 mg/L (Kaushal 2009). In Maryland, there is evidence that chloride concentrations in freshwater streams have been increasing (due to salt accumulation) over the last 40 years, including streams that enter Liberty Reservoir, a drinking water reservoir for Baltimore City (Kaushal et al. 2005). Figure 2 from that document is shown here with permission from the authors. Recent estimates from MBSS data of chloride concentrations in wadeable streams with minimal anthropogenic influence vary by ecological region and range between about 4 and 19 mg/L (Morgan et al. 2012). DNR’s

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long-term non tidal monitoring data show a statistically significant increasing trend in conductivity at 43 of 54 (80%) stations sampled (Figure 3). Salt concentrations in freshwater rivers and streams are likely related to stream size. Small streams tend to have higher concentrations than larger streams due to reduced capacities for dilution. Distance and position in relation to salt-treated roads also influences salt concentrations in rivers and streams. In Adirondack streams, (New York State), concentrations of salt downstream from roads were up to 31 times higher than upstream (Demers and Sage 1990).

Figure 2. Chloride concentrations of three tributaries to Liberty Reservoir (a drinking water reservoir) in Maryland. Taken by permission from Kaushal et al. (2005).

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Figure 3. Map of conductivity trends from Maryland DNR’s long-term non tidal monitoring.

Beginning in September 2011, DNR personnel deployed instruments that record stream conductivity (specific conductance) every hour in several Garrett and Allegany County streams. These conductivity loggers, which were deployed both upstream and downstream from roads, show vastly different specific conductance (specific conductance is temperature-corrected conductivity). Baseline concentrations for western Maryland streams are typically less than 100 uS/cm (Morgan et al. 2012). Specific conductance levels measured using a conductivity logger deployed by DNR in the Savage River approximately 8.1 kilometers downstream from Interstate 68 frequently exceeded 500 uS/cm (Figure 4). Interstate 68 is a major roadway running through Garrett County that is treated with salt in the winter. The Savage River specific conductance readings tended to be highest following snow fall events and were lowest when stream flow was higher (presumably due to dilution). During summer low flow periods (when the potential for dilution is at its lowest), the average conductivity remained above 330 uS/cm (Figure 5). Specific conductance was also recorded from a small tributary to the Casselman River in Garrett County upstream of any roads. Throughout the year, the specific conductance in this stream remained lower (less than 200 uS/cm) and less variable compared to the Savage River below Interstate 68.

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In addition to the ecological effects of road salt on freshwater streams, road salt also influences the potential of soil along roads to perform denitrification (Green et al. 2007). According to Endry et al. (2012), salt concentrations in stormwater as low as 80 mg/L had a significant influence on soil bacteria (compared to deionized water) and soil bacteria had a significant effect on effluent concentrations of nitrate, phosphate, copper, lead, and zinc. Thus, greater salt concentrations in roadside soils have the potential to increase nitrogen loading into nearby waters. The magnitude and extent of roadside soils containing salt could be an important factor to consider for meeting Maryland’s nutrient reduction goals and efforts to reduce nutrient run-off to Chesapeake Bay. Additionally, when roadside plant survival is adversely influenced by salt, increased erosion may occur, with more sediment in streams and ultimately Chesapeake Bay. Both short and long hydroperiod stormwater ponds have the potential to serve as long-term, year round sources of chloride and other toxins from road runoff to adjacent surface and ground waters. Since stormwater ponds are a point of recharge to ground and stream water, they may serve as road salt hotspots. As a result, pond ground water, floodplain groundwater, and stream water can be elevated in conductivity and chlorides throughout the year, not just during salt application and snow melt periods (Casey et al. 2012). Road salt can interact with other environmental factors causing increased toxicity to freshwater plants and animals (Gallagher et al. 2011; Cañedo-Argüelles et al. 2013). In relatively low concentrations, salt may ameliorate the influence of certain toxins in certain species. For example, 500 mg/L salinity reduced copper toxicity of up to 325 µg Cu/L to green frog (Lithobates clamitans) eggs and larvae (Brown et al. 2012). In select Baltimore streams, the concentration of chlorides in freshwater is correlated with impervious land cover in the watershed (Kaushal et al. 2005). Given the sensitivity of certain freshwater animals to salt-related toxicity, the higher salt concentrations with higher proportions of impervious land cover may contribute to the altered biological condition of streams observed with increasing levels of impervious land cover (e.g., Klein 1979; Schueler 1994; Stranko et al. 2008; Wenger et al. 2009). Salt-related toxicity in urban streams may also limit the degree of success achieved by stream restoration projects that focus primarily on physical changes, and may help explain the limited success so far for improving the biological condition of urban streams via restoration (Tullos et al. 2009; Violin et al. 2011; Stranko et al. 2012). Sensitivity of freshwater animals to salt Salinity is a major factor limiting the natural distribution of plants and animals (Williams 1987). Aquatic plants and animals differ substantially in their preferences and tolerances for salinity, resulting largely from their ability to balance salt concentrations in their tissues with that in the surrounding environment (osmoregulation). While most ocean dwelling animals require high levels of salinity to survive, the majority of freshwater species prefer water with very low concentrations of salt (e.g., less than 100 mg/L). We reviewed the salt and chloride toxicity literature of four freshwater animal groups (benthic macroinvertebrates, fish, amphibians, and mussels). We also included

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relationships between chloride and these animal groups drawn from MBSS data to show results that pertain most directly to DNR management goals and objectives. MBSS derived chloride data come from one time grab samples during spring base flow. While this likely provides a representation of chloride concentration, it does not characterize the highest levels streams likely experience during winter de-icing periods and during summer when the least dilution occurs. The MBSS chloride and biological data are displayed as scatterplots without statistical analyses. These scatterplots are informative and show patterns in the distribution of animals along a gradient of chloride concentration. Stream benthic macroinvertebrates According to results from field and laboratory studies, stream benthic macroinvertebrates, as a group, appear to be less sensitive to elevated concentrations of salt/chloride compared to some other freshwater animals. But there is a great deal of disparity among benthic macroinvertebrates in terms of their salinity tolerances (Blasius and Merritt 2002). Toxicity also depends on length of exposure. Long-term exposure is more harmful than acute exposure. Mayflies, stoneflies, and caddissflies are the most salt-sensitive stream insects (Hartman et al. 2005; Pond et al. 2008; Pond 2010). Certain dragonflies, crustaceans, beetles, and true flies tolerate the highest salt concentrations (Cañedo-Argüelles et al. 2013). Due to the variability in salinity tolerance across taxa, the highest insect richness in streams can occur at slightly elevated salinity levels (Kefford et al. 2011). In a literature review by Blasius and Merritt (2002), the most sensitive stream insects were affected by sodium chloride concentrations of approximately 800 mg/L (240 mg/L chloride) and many were not affected until concentrations exceeded 2,000 mg/L (800 mg/L chloride). MBSS results largely support findings from the literature. However, benthic macroinvertebrates may be more sensitive in Maryland, or other factors may be coupled with chloride here. Benthic macroinvertebrate index of biotic integrity (BIBI) scores appear to decline as chloride concentrations increase (Figure 6). No streams with BIBI scores higher than 4.0 (the threshold for the highest quality streams) had chloride concentrations above 190 mg/L. Only one stream with a chloride concentration above 500 mg/L had a BIBI score higher than 3.0. The 3.0 BIBI score is relevant here because watersheds with scores averaging less than 3.0 are included on Maryland’s List of Impaired Waters by the Maryland Department of the Environment (www.mde.state.md.us/programs/Water/TMDL/Integrated303dReports/Pages/Programs/WaterPrograms/TMDL/Maryland%20303%20dlist/index.aspx). Thus chlorides from road salt could be (at least partially) responsible for the listing of certain “impaired” streams in Maryland.

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Figure 6. Benthic macroinvertebrate index of biotic integrity (BIBI) scores and chloride concentrations from Maryland Biological Stream Survey sites sampled 2000 – 2011. The group of benthic macroinvertebrates in Maryland streams that tends to be most sensitive to pollution and watershed disturbance is the mayflies. The richness (number of genera) within this insect order declined with increasing chloride concentration at MBSS sites (Figure 7). Almost no mayflies were found in streams with chloride concentrations greater than 500 mg/L.

Fish Figure 7. Mayfly genus richness and chloride concentrations from Maryland Biological

Stream Survey sites sampled 2000 – 2011.

Freshwater fish Exposure to high levels of salinity for freshwater fish effects osmoregulation and breathing. Freshwater fishes have been shown to reduce food intake and conversion, as well as exhibit slower growth, when exposed to high levels of chlorides (Boef and Payan 2001). Salt is particularly deleterious to early life stages (sperm and eggs) of some fishes (Whiterod and Walker 2006). Studies have shown a wide range of salt tolerance among species of freshwater fishes (Cañedo-Argüelles et al. 2013). A recent paper (Morgan et al. 2012) used MBSS data to investigate the relationship between chloride and conductivity concentrations and fish in Maryland. They concluded that streams that are exposed to repeated, heavy road salting had increased stream conductivity and also displayed altered fish assemblages. Assemblages in streams where conductivities were highest consisted of only pollution tolerant and habitat generalist species. The authors further surmised that species declines and loss have likely resulted from high chloride and conductivity levels in some Maryland freshwater streams. Brook trout tend to be particularly sensitive to stream alterations and pollution compared to most other fish species in Maryland streams. Although the potential effects of temperature and sediment-related impacts that also accompany urbanization cannot be easily separated from the chloride signal, brook trout are only present in streams with chloride levels less than 280 mg/L (Figure 8). The highest densities of brook trout are found in streams with low chloride concentrations (less than 100 mg/L).

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Additionally, Uphoff et al. (2010, 2011) associated declines in anadromous fish spawning to increases in conductivity. They applied the 171 µmho/cm (1 µmho – 1µS/cm) criteria proposed by Morgan et al. (2007) to data from Piscataway and Mattawoman Creeks, and found Piscataway Creek exceeded this criterion over 90% of the time. The frequency of measurements greater than 171 µmho/cm varied in Mattawoman, with the greatest number of violations observed in 2009 after a significant snowfall event. Uphoff et al. (2012) reported spawning habitat losses in both watersheds, with spawning in Piscataway Creek observed at only one site out of five historically documented as spawning habitats and five out of seven in Mattawoman Creek.

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Amphibians As a group, amphibians tend to be more sensitive to salt compared with most other animals. This is probably because amphibians are poor osmoregulators (Dunlop et al. 2005). Pond breeding amphibians (especially those that could use stormwater ponds) may be at the highest risk from salt toxicity (Karraker et al. 2008) because salt can accumulate over time in these habitats. Pond-breeding species that place eggs on or near the bottom are at particular risk from road salt exposure, as their embryos will experience the highest salt concentrations and rates of mortality (Dobbs et al. 2012). Declines in survival of spotted salamanders have been documented at 145 mg/L chloride. Amphibian responses to salt in ponds may not always result in direct mortality but can have sublethal effects. High salt concentrations in ponds were correlated with malformations in green frogs (Lithobates clamitans) (Karraker 2007). We are not aware of any studies that specifically examined salt effects on stream salamanders. Based on MBSS data, the number of salamander species found in Maryland streams is lower with increasing chloride concentrations (Figure 9). No salamanders were found in streams with chloride concentrations above 440 mg/L, and no more than two species were found in any streams with chloride concentrations higher than 190 mg/L. While these results could represent urban-related influences other than chloride toxicity, the loss of species with increased chlorides is consistent with results from other studies of other amphibians, as described briefly above.

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Figure 9. Stream salamander species richness and chloride concentrations from Maryland Biological Stream Survey sites sampled 2000 – 2011.

Freshwater mussels Some freshwater mussels may be particularly sensitive to salt. Laboratory experiments have shown that certain species can be adversely affected at levels as low as 24 mg/L chloride (Bringolf et al. 2007). However, some species may be able to tolerate salt levels exceeding 1,500 mg/L (e.g., Bringolf et al. 2007; Valenti et al. 2007). To our knowledge, no studies have examined sodium chloride toxicity of mussels from Maryland and only one study included a Maryland species (Gillis 2011). According to MBSS data, although mussels were collected from 179 of 801 Maryland stream sites sampled from 2000 – 2011, no freshwater mussels were collected with chloride concentrations greater than 85 mg/L (Figure 10).

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Figure 10. Freshwater mussel species richness and chloride concentrations from Maryland Biological Stream Survey sites sampled 2000 – 2011.

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Regulations/policies/management plans USEPA, the Canadian Council of Ministers of the Environment, and many states within the U.S. set water quality limits or guidelines for chloride. According to USEPA water quality criteria, the “criterion maximum concentration” (short-term exposure) limit for freshwater should be less than 860 mg/L. The “criterion continuous concentration” (long-term exposure) should be less than 230 mg/L (USEPA 1988)(http://water.epa.gov/scitech/swguidance/standards/criteria/current/index.cfm). The Canadian Council of Ministers of the Environment recommends lower limits (640mg/L and 120 mg/L respectively) for short-term and long term exposure and recommends that more stringent limits be imposed where particularly rare or sensitive species are known to exist. Tim Fox (Maryland Department of the Environment, MDE) provided a table of chloride water quality criteria for U.S. states (Appendix B). Each state has a different approach to setting chloride concentration standards. In Iowa, for example, the standard for drinking water is 250 mg/L, but there is no numeric chloride standard for the protection of aquatic life. Instead, Iowa has adopted an equation-based approach to setting site specific chloride standards. Based on research indicating how the toxicity of chloride varies due to the hardness of the water and the concentrations of other anions, the Iowa Department of Natural Resources developed a set of equations in which the chloride criterion value is dependent upon both hardness and sulfate concentrations (Iowa Department of Natural Resources 2009). Calcium hardness and not total hardness seems to be the primary factor in ameliorating chloride toxicity based on Maryland data. Also, the sulfate expression in the Iowa equation was probably the result of the fact that decreasing sulfate reduces the overall toxicity of the ionic matrix, but does not specifically ameliorate the toxicity of chloride itself (Personal Communication, Tim Fox, MDE). In contrast, Texas applies a watershed approach, using use-attainability analyses to determine appropriate water quality standards for specified stream reaches. The chloride criteria for stream segments are given in Chapter 307, Appendix A of the Texas Administrative Code (2010) as maximum annual averages for individual stream segments. These vary widely, from as little as 50 mg/L to 37,000 mg/L. Wyoming applies the federal chloride standards for aquatic life to specially classified waters (e.g., waters for drinking, water that supports game fisheries, or that are considered “outstanding enough to prevent any further degradation”). However, Wyoming also applies site specific standards to waters, with unique attributes making the general criteria unsuitable. Site specific standards for instantaneous maximum chloride standards range from 531 mg/L to 1600 mg/L (http://deq.state.wy.us/wqd/wqdrules/Chapter_01.pdf ). States have also collaborated to determine water quality standards for large river basins that cross state lines. The Delaware River Basin Commission, which includes participants from Delaware, New Jersey, Pennsylvania, and New York, has classified certain waters as special protection waters due to either outstanding quality or resource significance. In waters designated as such, no statistically significant decrease in water quality is allowed.

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Therefore, the concentration limits on chloride and other chemicals are based on median values as defined by the DRBC Water Quality Regulations Administrative Manual. The median values for chlorides referenced in this document range from as little as 8.9 mg/L to as high as 48 mg/L. The DRBC has also set water quality regulations for specific zones along the Delaware River. Of these zones, only the first two occurring in the tidal portion of the Delaware River, Zones 2 and 3, have numeric standards for chloride concentration. In Zone 2, the maximum 15-day average for chloride concentration is 50 mg/L. In Zone 3 at river mile 98, the maximum 15-day average for chloride concentration is 180 mg/L. Currently, there are no water quality criteria for chloride or sodium chloride in Maryland. But, the MDE is working on developing state-specific criteria. MDE also requires certain counties to control the overuse of winter weather de-icing materials. Certain counties, municipalities, and Maryland’s State Highway Administration (SHA) must also report the quantity of de-icing chemicals used as a requirement for receiving a National Pollution Discharge Elimination System (NPDES) permit (Maryland Department of the Environment 2004).

In January 2013, the Chesapeake Bay Commission (CBC) reviewed road salt policies in Maryland, Pennsylvania, and Virginia to see if additional policy action was necessary to protect resources (Chesapeake Bay Commission 2013). The consensus was that “indiscriminate application of road salt does not typically occur”. Additionally, due to the increasing cost of road salts, it is in the best interest of State transportation agencies to balance public safety concerns with salt application. Although the CBC document acknowledged environmental and drinking water threats from road salt application, no significant policy actions were deemed necessary. The CBC document concluded that the best way to address the environmental impacts associated with snow and ice removal is to more effectively control stormwater runoff and minimize the creation of impervious surfaces. In response to two bills (House Bill 0903, Senate Bill 0775; Maryland State Legislature 2010a,b ) passed by the Maryland State Legislature in 2010, the State Highway Administration (SHA), in conjunction with MDE, were required to establish a statewide Salt Management Plan. This plan includes several best management practices for use by the state and local jurisdictions to minimize the adverse environmental impacts of road salt runoff. The SHA plan (MD State Highway Administration 2012) states that the best practices described in the plan “should be seen as a starting point management plan to minimize the impact of salt on the environment in Maryland.” The SHA plan also states that “best practices for salt management should be a living document that is updated on a regular basis.” Recent information from SHA indicates that they are continuing to test and evaluate new winter materials, equipment and strategies in an ongoing effort to improve the level of service provided to motorists during winter storms while at the same time minimizing the impact of its operations on the environment. Reducing the environmental effects Many Best Management Practices are available for potentially reducing the environmental effects of road salt that include, but are not limited to, methods for improving application efficiency and using alternative de-icing chemicals. The

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Minnesota Pollution Control Agency also offers ways to “reduce salt use while maintaining high safety standards” on their web site (www.pca.state.mn.us). Examples include using sand to improve traction and removing excess salt. There is strong and consistent scientific evidence for environmental problems associated with road salt applications. Balancing public safety with environmental protection could become a significant challenge as accumulating concentrations of salt in our freshwater continues to threaten the environment and drinking water supplies. It is possible that by managing and, in some areas limiting, road salt use now, we may be able to halt the steady increase in surface and ground water concentrations (Jin et al. 2011). Summary and conclusions As supported by many scientific studies, road salt is contributing to long-term salinization of streams of the northeastern U.S (including Maryland). Salinization appears to alter the ecological condition of freshwater stream ecosystems in many places including Maryland. A preliminary examination of data collected by the Maryland Biological Stream Survey indicated that benthic macroinvertebrates, fish, salamander, and freshwater mussel richness respond negatively to elevated chloride concentrations. Consistent with other studies, amphibians and freshwater mussels seem to be the most sensitive stream-dwelling animals. The Canadian Council of Ministries of the Environment and several U.S. states have set water quality limits or guidelines for chloride. MDE is working toward chloride water quality criteria for Maryland waters, but none exist at this time. The Maryland State Highway Administration (SHA), in conjunction with MDE established a statewide Salt Management Plan in October 2011. This plan includes several best management practices that SHA is required to use and State and local jurisdictions are encouraged to use to minimize the adverse environmental impacts of road salt runoff. Some other practices also exist and could be considered. There are strong relationships between impervious surface and chloride concentrations. If road salt continues to be applied to Maryland roadways at its current rate, salt concentrations in freshwater streams and drinking water reservoirs will continue to increase. But, by more aggressively managing and in some cases limiting, road salt use now, we may be able to halt, or at least slow, this increase.

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Acknowledgements We thank Robert Hilderbrand, Sujay Kaushal, Sandy Hertz, Sherm Garrison, David Goshorn, and Bruce Michael for reviewing this document. We also thank Frank Dawson for bringing this topic to our attention. We thank Tim Fox for his review and for data and information he contributed. Our gratitude is also extended to the Maryland Department of Natural Resources Maryland Biological Stream Survey sampling crews who collected the water samples and biological data discussed herein. Ray Morgan and Katie Kline provided support via laboratory analyses of water samples collected at MBSS sites.

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of road salt (NaCl) on stream macroinvertibrate communities. Environmental Pollution 120:219-231.

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Gillis, P.L. 2011. Assessing the toxicity of sodium chloride to the glochidia of freshwater mussels: Implications for salinization of surface waters." Environmental Pollution 159.6 : 1702-1708.

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Green, S.M., R. Machin, and M.S. Cresser. 2006. Effect of long-term changes in soil

chemistry induced by road salt applications on N-transformations in roadside solids. Environmental Pollution 152:20-31.

Harte P.T. and P.R. Throwbridge. 2010. Mapping of road-salt contaminated groundwater

discharge and estimation of chloride load to a small stream in southern New Hampshire, USA. Hydrological Processes 24:2349-2368.

Hartman, K., M. Kaller, J. Howell, and J. Sweka. 2005. How much do valley fills

influence headwater streams? Hydrobiologia 532:91 -102. Iowa Department of Natural Resources. 2009. Water Quality Standards Review:

Chloride, sulfate, and total dissolved solids. http://www.iowadnr.gov/ Accessed February 7, 2013.

Jackson, R. B. and E.G. Jobàggy. 2005. From icy roads to salty streams. Proceedings of

the National Academy of Sciences 102:14487-14488. Jin, L., P. Whitehead, D.I. Siegel, and S. Findlay. 2011. Salting our landscape: An

integrated catchment model using readily accessible data to assess emerging road salt contamination to streams. Environmental Pollution 159:1257-1265.

Karraker, N.E. 2007. Are embryonic and larval green frogs (Rana clamitans) insensitive

to road deicing salt? Herpetological Conservation and Biology 2: 35-41. Kaushal, S.S. 2009. Chloride. In: Gene E. Likens, (Editor) Encyclopedia of Inland

Waters 2:23-29 Oxford: Elsevier. Kaushal, S.S., P.M. Groffman, G.E. Likens, K.T. Belt, W.P. Stack, V.R. Kelly,L.E. Band, and G.T. Fisher. 2005. Increased salinization of fresh water in the northeastern United States. Proceedings of the National Academy of Sciences 102:13517– 13520. Kefford, B.J., Marchant, R., Schäfer, R.B., Metzeling, L., Dunlop, J.E., Choy, S.C.,

Goonan, P. 2011. The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates. Environmental Pollution 159: 302-310.

20

Kelly, V.R., G.M. Lovett, K.C. Weathers, S.E.G. Findlay, D.L. Strayer, D.J. Burns, and G.E. Likens. 2007. Long-term sodium chloride retention in a rural watershed: legacy effects of road salt on streamwater concentration. Environmental Science & Technology 42: 410–415. Klein, R. 1979. Urbanization and stream quality impairment. American Water Resources

Association Water Resources Bulletin 15:948–963. Maryland Department of the Environment. 2004. National Pollutant Discharge

Elimination System, Municipal Separate Storm Sewer System Discharge Permit 99-DP-3313, MD0068276.

MD State Highway Administration. 2012. Statewide Salt Management Plan. 151 pgs. MD State Legislature. 2010a. House Bill 0903: Transportation—Road Salt

Management—Best Practices Guidance (Delegates Kramer et al.). http://mgaleg.maryland.gob/2010rs/chapters_noln/Ch_607_hb0903Y.pdf MD State Legislature 2010b. Senate Bill 0775: Transportation—Road Salt

Management—Best Practices Guidance (Delegates Kramer et al). http://mgaleg.maryland.gov/2010rs/fnotes/bil_005/sb0775.pd Morgan, R. P., K. M. Kline, and S. F. Cushman. 2007. Relationships among nutrients,

chloride and biological indices in urban Maryland streams. Urban Ecosystems0:153-166.

Morgan, R., K.M. Kline, M.J. Kline, S.F. Cushman, M.T. Sell, R.E. Weitzell Jr. and J.B. Churchill. 2012. Stream conductivity: Relationships to land use, chloride, and fishes in Maryland streams. North American Journal of Fisheries Management 32:941-952. Perera, N., B. Gharabaghi, and K. Howard. 2013. Groundwater chloride response in the

Highland Creek watershed due to road salt application: A re-assessment after 20 years. Journal of Hydrology 479(159-168).

Pond, G.J. 2010. Patterns of Ephemeroptera taxa loss in Appalachian headwater streams

(Kentucky, USA). Hydrobiologia 641: 185-201. Pond, G.J. 2011. Biodiversity loss in Appalachian headwater streams (Kentucky, USA):

Plecoptera and Trichoptera communities. Hydrobiologia 679:97-117. Schueler, T.R. 1994. The importance of imperviousness. Watershed Protection

Techniques 1:100–111. Stranko, S. A., R. H. Hilderbrand, R. P. Morgan III, M. W. Staley, A. J. Becker, A.

Roseberry-Lincoln, E. S. Perry, and P. T. Jacobson. 2008. Brook trout declines

21

with changes to land cover and temperature in Maryland. North American Journal of Fisheries Management 28:1223–1232.

Stranko, S.A., R. H. Hilderbrand, M. and A. Palmer. 2012. Comparing the Fish and

Benthic Macroinvertebrate Diversity of Restored Urban Streams to Reference Streams. Restoration Ecology 20:747–755.

Tullos, D. D., D. L. Penrose, G. D. Jennings, and W. G. Cope. 2009. Analysis of

functional traits in reconfigured channels: implications for the bioassessment and disturbance of river restoration. Journal of the North American Benthological Society 28:1–80.

Uphoff, J., M. McGinty, R. Lukacovic, J. Mowrer, and B. Pyle. 2010. Development of

habitat based reference points for Chesapeake Bay fishes of special concern: Impervious surface as a test case. Chesapeake Bay Finfish/Habitat Investigations 2009, Project 3. Maryland Department of Natural Resources, Annapolis, Maryland.

Uphoff, J., M. McGinty, R. Lukacovic, J. Mowrer, and B. Pyle. 2011. Marine and estuarine finfish ecological and habitat investigations. Performance Report for Federal Aid Grant F-63-R, Segment 2. Maryland Department of Natural Resources, Annapolis,Maryland.

Uphoff, J., M. McGinty, R. Lukacovic, J. Mowrer, and B. Pyle. 2012. Marine and estuarine finfish ecological and habitat investigations. Performance Report for Federal Aid Grant F-63-R, Segment 2, 2011. Maryland Department of Natural Resources, Annapolis,Maryland

USEPA. 1988. Ambient Water Quality Criteria for Chloride. Office of Water, Regulations and Standards Criteria and Standards Division, Washington, DC 20460. EPA-440/5-88-001.

Valenti, T.W., D.S. Cherry, R.J. Neves, B.A. Locke, and J.J. Schmerfeld. 2007. Case study: Sensitivity of mussel glochidia and regulatory test organisms to mercury and a reference toxicant. Freshwater Bivalve Ecotoxicology. Farris, J.L., and J.H. Van Hassel (eds). CRC Press. pp. 351-367.

Violin, C.R., P. Cada, E.B. Sudduth, B.A. Hassett, D.L. Penrose, and E.S. Bernhardt.

2011. Effects of urbanization and urban stream restoration on the physical and biological structure of stream ecosystems. Ecological Applications 21:1932–1949.

Wenger, S.J., A.H. Roy, C.R. Jackson, E.S. Bernhardt, T.L. Carter, S. Filoso, C.A.

Gibson, W.C. Cully, S.S. Kaushal, E. Marti, J.L. Meyer, M.A. Palmer, M.J. Paul, A.H. Purcell, A. Ramirez, A.D. Rosemond, K.A. Schofield, E.B. Sudduth, and C.J. Walsh. 2009. Twenty-six key research questions in urban stream ecology: an assessment of the state of the science. Journal of the North American Benthological Society 28:1080–1098.

22

Whiterod, N.R., and K.F. Walker. 2006. Will rising salinity in the MurrayeDarling Basin affect common carp (Cyprinus carpio L.)? Marine and Freshwater Research 57: 817-823.

Williams, W.D. 1987. Salinization of Rivers and streams: an important environmental

hazard. Ambio 16:181-185.

23

Appendix A Bibliography of

Ecological Effects of Road Salt

Compiled and edited by

Jennifer Zimmerman Maryland Department of Natural Resources

Maryland Department of Natural Resources Annapolis, MD

2013

24

Amphibians: Brown, M.G. et al. 2012. Ameliorative effects of sodium chloride on acute copper

toxicity among cope’s gray tree frog (Hyla chrysoscelis) and green frog (Rana clamitans) embryos. Environmental Toxicology and Chemistry 31:836–842.

Collins, S.J. and R.W. Russell. 2009. Toxicity of road salt to Nova Scotia amphibians.

Environmental Pollution 157: 320-324. Dobbs, E.K., M.G. Brown, J.W. Snodgrass and D.R. Ownby. 2012. Salt toxicity to tree

frogs (Hyla chrysoscelis) depends on depth. Herpetologica 68:22–30. Karraker, N.E. 2007. Are embryonic and larval green frogs (Rana clamitans) insensitive

to road deicing salt? Herpetological Conservation and Biology 2:35-41. Karraker, N.E., J.P. Gibbs, and J.R. Vonesh. 2008. Impacts of road deicing salt on the

demography of vernal pool-breeding amphibians. Ecological Applications 18:724-734.

Sanzo, D. and S. J. Hecnar. 2006. Effects of road de-icing salt (NaCl) on larval wood

frogs (Rana sylvatica). Environmental Pollution 140:247-256. Benthic macroinvertebrates: Bartlett, A.J., Q. Rochfort, L.R. Brown, and J. Marsalek. 2011. Causes of toxicity to

Hyalella azteca in a stormwater management facility receiving highway runoff and snowmelt Part I: polycyclic aromatic hydrocarbons and metals. Science of the Total Environment 414:227-237.

Bartlett, A.J., Q. Rochfort, L.R. Brown, and J. Marsalek. 2011. Causes of toxicity to

Hyalella azteca in a stormwater management facility receiving highway runoff and snowmelt. Part II:Salts, nutrients, and water quality. Science of the Total Environment 414:238-247.

Benbow, M.E. and R.W. Merritt. 2004. Road-salt toxicity of select Michigan wetland

macroinvertebrates under different testing conditions. Wetlands 24:68-76. Blasius, B.J. and R.W. Merritt. 2002. Field and laboratory investigations on the effects

of road salt (NaCl) on stream macroinvertibrate communities. Environmental Pollution 120:219-231.

Crowther, R.A., and H.B.N. Hynes. 1977. The effect of road deicing salt on the drift of

stream benthos. Environmental Pollution 14:113-126. Pond, G.J. 2010. Patterns of Ephemeroptera taxa loss in Appalachian headwater streams

(Kentucky, USA). Hydrobiologia 641: 185-201.

25

Pond, G.J. 2011. Biodiversity loss in Appalachian headwater streams (Kentucky, USA): Plecoptera and Trichoptera communities. Hydrobiologia 679:97-117.

Fish: Morgan, R., K.M. Kline, and S.F. Cushman. 2006. Relationships among nutrients, chloride and biological indices in urban Maryland streams. Urban Ecosystem 10:153-166. Morgan, R., K.M. Kline, M.J. Kline, S.F. Cushman, M.T. Sell, R.E. Weitzell Jr. and J.B. Churchill. 2012. Stream conductivity: Relationships to land use, chloride, and fishes in Maryland streams. North American Journal of Fisheries Management 32:941-952. Government Report: Baltimore County National Pollution Discharge Elimination System (NPDES). 2011. Baltimore County NPDES-Municipal Stormwater Discharge Permit 2011 Annual Report. http://www.baltimorecountymd.gov/Agencies/environment/npdes/index.html Accessed on February 5, 2013. Guidelines: Canadian Council of Ministers of the Environment. 2011. Canadian water quality

guidelines for the protection of aquatic life: Chloride. Canadian Environmental Quality Guidelines.

E. Stimson. 2004 memorandum to D. Williams, Montana Department of Transportation

Environmental Services, on Chloride levels in streams adjacent to winter maintenance activities.

Environmental Canada. 1999. Priority substances assessment report: Road salts.

http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/contaminants Accessed on February 2, 2013.

Soil: Bai, J, R. Xiao, J. Wang, and C. Huang. 2012. A review of soil nitrogen mineralization as

affected by water and salt in coastal wetlands: Issues and methods. Clean-Soil, Air, Water 40:1099-1105.

Green, S.M., R. Machin, and M.S. Cresser. 2006. Effect of long-term changes in soil

chemistry induced by road salt applications on N-transformations in roadside solids. Environmental Pollution 152:20-31.

26

Groffman, P.M., A.J. Gold, G. Howard. 1995. Hydrologic tracer effects on Soil Microbial Activities. Social Science Society of America Journal 59:478-481.

State Standards: Advent-Environ. 2007. Evaluation of chloride water quality criteria protectiveness of

upper Santa Clara River aquatic life: An emphasis on threatened and endangered species. Prepared for Sanitation Districts of Los Angeles County. http://www.lacsd.org/civica/filebank/blobdload.asp. Accessed on February 5, 2013.

Colorado River Basin Salinity Control Forum. 2005. 2005 Review water quality

standards for salinity-Colorado river system. http://www.crb.ca.gov/Salinity/2011/2011%20REVIEW-June%20Draft.pdf. Accessed on February 6, 2013.

Commonwealth of Pennsylvania Department of Environmental Protection Bureau of

Point and Non-point Source Management. Rationale for the development of ambient water quality criteria for chloride-protection of aquatic life use. http://files.dep.state.pa.us/PublicParticipation/. Accessed on February 7,2013.

Delaware River Basin Commission. 2010. Administrative manual – Part III water quality

regulations with amendments through December 8, 2010. 18 CFR part 410. http://www.state.nj.us/drbc/library/documents/WQregs.pdf. Accessed on February 7, 2013.

Pennsylvania Department of Environmental Protection. 2010. Evaluation of water

quality criteria for aquatic life use protection-chloride for Pennsylvania. Rationale Document. http://files.dep.state.pa.us/water/Drinking. Accessed on February 7, 2013.

Indiana Department of Environmental Management. 2012. Chloride and sulfate water

quality criteria amendments fact sheet. http://www.in.gov/idem/files/wpcb_2012_mar_11-320_factsheet.pdf. Accessed on February 7, 2013.

Iowa Department of Natural Resources. 2009. Water Quality Standards Review:

Chloride, sulfate, and total dissolved solids. http://www.iowadnr.gov/portals/idnr/uploads/water/standards/ws_review.pdf. Accessed February 7, 2013.

Kansas Department of Health and Environment Bureau of Environmental Field Sciences.

2001. Guidance document for use attainability analyses (UAAs). http://www.kdheks.gov/befs/uaas/UAAGuidance.pdf. Accessed February 4, 2013.

27

Kansas Department of Health and Environment. 2000. Lower Arkansas River basin total maximum daily load. http://www.wichita.gov/NR/rdonlyres/. Accessed February 4, 2013.

Monson, P. 2012. Draft chloride aquatic life water quality standards technical support

document for chloride. http://www.pca.state.mn.us/index.php/view-document.html. Accessed on February 7, 2013.

National Cooperative Highway Research Program. 2004. Snow and ice control:

Guidelines the selection of snow and ice control materials to mitigate environmental impacts. http://onlinepubs.trb.org/onlinepubs/nchrp. Accessed on February 2, 2013.

Sindt, G. 2008. Chloride and TDS water quality standards update.

http://www.iawea.org/sites/default/files/. Accessed on February 7, 2013. Sindt, G. 2011. Chloride and ammonia water quality standards update.

http://www.meatami.com/ht/a/GetDocumentAction/i/67504. Accessed on February 7, 2013.

Siegel, L. 2007. Hazard identification for human and ecological effects of sodium

chloride road salt. http://www.rebuildingi93.com/documents/environmental/. Accessed on February 7, 2013.

Texas Commission on Environmental Quality. 2010. Chapter 307-Texas surface water

quality standards. http://water.epa.gov/scitech/swguidance/standards/. Accessed on February 7, 2013.

Thornton, K, I. Ivanciu, and J. Heeren. 2011. Penndot strategic environmental management program. 2011 TRB Waste Management and Resource Efficiency Workshop. http://environment.transportation.org/pdf/. Accessed on February 11, 2013. Throwbridge, P., J.S. Kahl, D.A. Sassan, D.L. Heath and E.M. Walsh. 2010. Relating

road salt to exceedances of the water quality standard for chloride in New Hampshire streams. Environmental Science & Technology 44:13. http://pubs.acs.org/doi/abs/. Accessed February 7, 2013.

Colorado River Basin Salinity Control Forum. 2005. Water quality standards for

salinity Colorado river system. http://www.crb.ca.gov/Salinity/2011/. Accessed on February 7, 2013.

Whipps, B. 2011. Changes to chloride criteria in Missouri’s water quality standards. http://www.showmeboone.com/stormwater/documents/. Accessed February 7, 2013.

28

World Health Organization. 2006. Guidelines for drinking-water quality. http://www.who.int/water_sanitation_health/. Accessed February 7, 2013. Wyoming Department of Environmental Quality. 2004. Water quality rules and regulations-Wyoming surface water quality standards. http://soswy.state.wy.us/rules/RULES. Accessed on February 7,2013. Stormwater: Casey, R.E., S.M. Lev, and J.W. Snodgrass. 2012. Stormwater ponds as a source of long-

term surface and ground water salinisation. Urban Water Journal 1-9. Endreny, T., D.J. Burke, K.M. Burchhardt, M.W. Fabian, and A.M. Kretzer. 2012.

Bioretention column study of bacteria community response to salt-enriched artificial stormwater. Journal of Environmental Quality 41:1951-1959.

Endreny, T., D.J. Burke, K.M. Burchhardt, M.W. Fabian, A.M. Kretzer, and T.Endreny.

2012. Bacteria community response to salt-enriched artificial stormwater. Journal of Environmental Quality

Gallagher, M.T., J.W. Snodgrass, D.R. Ownby, A.B. Brand and R.E. Casey. 2001. Watershed-scale analysis of pollutant distributions in stormwater management ponds. Urban Ecosystems 14:469-484. Marsalek, J. 2003. Road salts in urban stormwater: An emerging issue in stormwater management in cold climates. Water Science and Technology 48:61-70 Mayer, T. 2007. Geochemistry and toxicity of sediment porewater in a salt-impacted urban stormwater detention pond. Environmental Pollution 156:143-151. Van Meter, R. J., C. M. Swan and J. W. Snodgrass. In press. 2011. Salinization alters ecosystem structure in urban stormwater detention ponds. Urban Ecosystems 14:723–736. Water Quality: Demers, C. L. and R.W. Sage Jr. 1990. Effects of road salt on chloride levels in four

Adirondack streams. Water, Air, and Soil Pollution 49:369-373. Kaushal, S.S. 2009. Chloride. In: Gene E. Likens, (Editor) Encyclopedia of Inland

Waters 2:23-29 Oxford: Elsevier. Kelly, V.R., G.M. Lovett, K.C. Weathers, S.E.G. Findlay, D.L. Strayer, D.J. Burns, and G.E. Likens. 2007. Long-term sodium chloride retention in a rural watershed: legacy effects of road salt on streamwater concentration. Environmental Science & Technology 42: 410–415.

29

Mullaney, J.R., D.L. Lorenz, and A.J. Arntson. 2009. Chloride in groundwater and surface water in areas underlain by the glacial aquifer system, Northern United States. U.S. Geological Survey Scientific Investigations Report 2009–5086: 41.

Perera, N., B. Gharabaghi, and K. Howard. 2013. Groundwater chloride response in the

Highland Creek watershed due to road salt application: A re-assessment after 20 years. Journal of Hydrology 479:159-168.

Soucek, D.J. 2007. Comparison of hardness- and chloride-regulated acute effects of

sodium sulfate on two freshwater crustaceans. Environmental Toxicology and Chemistry 26:773-779.

Soucek, D.J., and A.J. Kennedy. 2005. Effects of hardness, chloride, and acclimation on

the acute toxicity of sulfate to freshwater invertebrates. Environmental Toxicology and Chemistry 24:1204-1210.

Soucek, D.J., T. K. Linton, C. D. Tarr, A. Dickinson, N. Wickramanayake, C.G. Delos, and L.A. Cruz. 2011. Influence of water hardness and sulfate on the acute toxicity of chloride to sensitive freshwater invertebrates. Environmental Toxicology and Chemistry 30:930-938. Transportation Research Board. 1991. Highway deicing-comparing salt and calcium magnesium acetate. Committee on the Comparative Costs of Rock Salt and Calcium Magnesium Acetate (CMA) for Highway Deicing. Special Report 235, Washington, D.C. Miscellaneous: Cañedo-Argüelles, M., B.J. Kefford, C. Piscart, N. Prat, R.B. Schäfer, and C.-J. Schulz, 2013. Salinisation of rivers: An urgent ecological issue. Environmental Pollution 173:157-167.

Elshahed, M.S., F.Z. Najar, B.A. Roe, A. Oren, T.A. Dewers, and L.R. Krumholz. 2004. Survey of archael diversity reveals an abundance of halopholic archea in a low-salt, sulfide- and sulfur-rich spring. Applied and Environmental Microbiology 70: 2230-2239.

Forman, R.T.T. 2000. Estimate of the area affected ecologically by the road system in the

United States. Conservation Biology 14:31-35.

30

Forman, R.T.T. and , R.D Deblinger. 1998. The ecological road-effect zone for transportation planning and Massachusetts highway example. International Conference on Wildlife Ecology and Transportation: 78-96. February 9-12, 1998.

Forman, R.T.T. and R. D. Deblinger. 2000. The ecological road-effect zone of a

Massachusetts (U.S.A.) suburban highway. Conservation Biology 14:36-46. Gillis, P. 2011. Assessing the toxicity of sodium chloride to glochidia of freshwater

mussels: Implications for salinization of surface waters. Environmental Pollution 159:1702-1708.

Hemphill, S. 2009. Winter road salts ending up in lakes and streams. Minnesota Public Radio (February 11). Jackson, R. B. and E.G. Jobàggy. 2005. From icy roads to salty streams. Proceedings of the National Academy of Sciences 102:14487-14488. Jin, L., P. Whitehead, D.I. Siegel, and S. Findlay. 2011. Salting our landscape: An integrated catchment model using readily accessible data to assess emerging road salt contamination to streams. Environmental Pollution 159:1257-1265. Kaushal, S.S. and K.T. Belt. 2012. The urban watershed continuum: evolving spatial and temporal dimensions. Urban Ecosystems 15:409-435. Kaushal, S.S., P.M. Groffman, G.E. Likens, K.T. Belt, W.P. Stack, V.R. Kelly,L.E. Band, and G.T. Fisher. 2005. Increased salinization of fresh water in the northeastern United States. Proceedings of the National Academy of Sciences 102:13517– 13520. Kelly, V. R., S.E.G. Findlay, W.H. Schlesinger, K. Menking, and A.M. Chatrchyan. 2010. Road salt: moving toward the solution. The Cary Institute of Ecosystem Studies Special Report. Meadows, R. Road salt turns streams toxic. Conservation Magazine 102:13517-13520. Meriano, M., N. Eyles, and K.W.F. Howard. 2009. Hydrogeological impacts of road salt from Canada’s busiest highway on Lake Ontario watershed (Frenchman’s Bay) and lagoon, City of Pickering. Journal of Contaminant Hydrology 107:66-81. Stephens, Guy. 1998. Studies find less biodiversity when road salt reaches waterways,

Satellite maps show effects of development on weather, and more… Bay Journal. April 1, 1998.

Timpano, A.J., S. Schoenholtz, C. Zipper, and D. Soucek. 2011. Levels of dissolved solids associated with aquatic life effects in headwater streams of Virginia’s central Appalachian coalfield region. Virginia Tech Report.

31

Van Meter, R.J., C.M. Swan, J. Leips, and J.W. Snodgrass. 2011. In press. Road salt stress induces novel food web structure and interactions. Wetlands 31:843–851 Wegner, W. and M. Yaggi. 2001. Environmental impacts of road salt and alternatives in the New York City watershed. Stormwater May/June Issue. Weygand, J. 2012. Save our streams, lakes, and rivers: Use less road salt. Daily Planet. (February 16, 2012).

32

Appendix B. Table of state chloride criteria from Tim Fox, Maryland Department of the Environment.

Criteria Maximum Concentration Criteria Continuous Concentration Link to document explaning the criteria if available.Alabama NA NA http://adem.alabama.gov/alEnviroRegLaws/files/Division6Vol1.pdf

Alaska 860 230

http://dec.alaska.gov/water/wqsar/wqs/pdfs/Alaska%20Water%20Quality%20Criteria%20Manual%20for%20Toxic%20and%20Other%20Deleterious%20Organic%20and%20Inorganic%20Substances.pdf

Arizona NA NAhttp://www.azdeq.gov/environ/water/standards/download/SWQ_Standards-1-09-unofficial.pdf

Arkansas site specific site specific http://www.adeq.state.ar.us/water/branch_planning/wqs_review.htmCalifornia NA NA http://www.waterboards.ca.gov/mywaterquality/water_quality_standards/Colorado site specific (most are 250) http://www.cdphe.state.co.us/regulations/wqccregs/Connecticut NA NA http://www.ct.gov/dep/lib/dep/water/water_quality_standards/wqs.pdf

Delaware NA NAhttp://www.dnrec.state.de.us/DNREC2000/Divisions/Water/WaterQuality/WQStandard.pdf

Florida 250 or 10% deviation http://www.dep.state.fl.us/legal/Rules/shared/62-302/62-302.pdfGeorgia NA NA http://rules.sos.state.ga.us/docs/391/3/6/03.pdfHawaii NA NA http://gen.doh.hawaii.gov/sites/har/AdmRules1/11-54.pdfIdaho NA NA http://adminrules.idaho.gov/rules/current/58/0102.pdf

Illinois NA NAhttp://www.epa.state.il.us/water/water-quality-standards/water-quality-criteria-list.pdf

Indiana 860 230 http://www.in.gov/legislative/iac/T03270/A00020.PDF

Iowa New Data New Datahttp://www.iowadnr.gov/InsideDNR/RegulatoryWater/WaterQualityStandards/ChemicalCriteria.aspx

Kansas 860 under investigation http://www.kdheks.gov/water/download/kwqs_plus_supporting.pdfKentucky 1200 600 http://lrc.ky.gov/kar/401/010/031.htm

Louisiana site specifichttp://water.epa.gov/scitech/swguidance/standards/upload/2007_10_16_standards_wqslibrary_la_la_6_wqs.pdf

Maine 860 230 http://www.maine.gov/sos/cec/rules/06/chaps06.htmMaryland NA NAMassachusetts 860 230Michigan NA NA http://www.michigan.gov/documents/deq/wrd-swas-rule57_372470_7.pdfMinnesota 860 230 https://www.revisor.mn.gov/rules/?id=7050.0220

Mississippi site specifichttp://www.deq.state.ms.us/mdeq.nsf/pdf/WMB_adopted_wqsstandoc_aug07/$File/WQS_std_adpt_aug07.pdf?OpenElement

Missouri Iowa equations http://www.sos.mo.gov/adrules/csr/current/10csr/10c20-7a.pdfMontana NA NA http://deq.mt.gov/wqinfo/Standards/default.mcpx

Nebraska 860 230http://www.deq.state.ne.us/RuleAndR.nsf/23e5e39594c064ee852564ae004fa010/9f07eae313ae56d686256888005bc61e/$FILE/T117Ch4_4.1.12.pdf

Nevada 250 but also site specific for high water quality http://www.leg.state.nv.us/nac/nac-445a.html#NAC445ASec118

New Hampshire 860 230http://des.nh.gov/organization/commissioner/legal/rules/documents/env-wq1700.pdf

New Jersey 860 230 http://www.nj.gov/dep/rules/rules/njac7_9b.pdfNew Mexico some site specific 250 http://www.nmcpr.state.nm.us/nmac/parts/title20/20.006.0004.pdfNew York 250 http://www.dec.ny.gov/regs/4590.html

North Carolina 230 action levelhttp://portal.ncdenr.org/c/document_library/get_file?uuid=ad77b198-aa3d-4874-9723-54ce730b3a8d&groupId=38364

North Dakota 100 or 250 in some areas but also incorporate Na into standards! http://www.legis.nd.gov/information/acdata/pdf/33-16-02.1.pdfOhio NA http://www.epa.ohio.gov/portals/35/rules/01-07.pdf

Oklahoma site specifichttp://www.owrb.ok.gov/util/rules/pdf_rul/RulesCurrent2011/Ch45-Current2011.pdf

Oregon 860 230 http://www.deq.state.or.us/wq/standards/toxics.htm#CurPennsylvania 250pws http://www.pacode.com/secure/data/025/chapter93/chap93toc.htmlRhode Island 860 230 http://www.dem.ri.gov/pubs/regs/regs/water/h2oq10.pdfSouth Carolina NA NA http://www.scdhec.gov/environment/water/regs/r61-68.pdfSouth Dakota NA NA http://legis.state.sd.us/rules/DisplayRule.aspx?Rule=74:51:01:0B

Tennessee 250http://southeastaquatics.net/uploads/category/TDECWaterQualityStandards.pdf

Texas site specific http://www.tceq.texas.gov/assets/public/legal/rules/rules/pdflib/307%60.pdfUtah NA NA http://www.rules.utah.gov/publicat/code.htm#EnvironmenVermont NA http://www.nrb.state.vt.us/wrp/publications/wqs.pdf

Virginia 860 230http://www.deq.state.va.us/Portals/0/DEQ/Water/WaterQualityMonitoring/TOX/2012/Appendices/Appendix_A_DEQ_Water_Quality_Standards_Jan2011.pdf

Washington 860 230 http://apps.leg.wa.gov/WAC/default.aspx?cite=173-201A-240

West Virginia 860 230 http://www.dep.wv.gov/WWE/getinvolved/sos/Documents/WQS/Standards.pdfWisconsin 757 395 http://dnr.wi.gov/org/water/wm/wqs/wqbel.htmWyoming 860 230 http://soswy.state.wy.us/Rules/RULES/6547.pdf

Chloride Criteria

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